1. Field of the Invention
One embodiment of the present invention relates to a display device. One embodiment of the present invention relates to a method for manufacturing a display device.
Note that one embodiment of the present invention is not limited to the above technical field. One embodiment of the present invention relates to, for example, an object, a method, or a manufacturing method. The present invention relates to a process, a machine, manufacture, or a composition of matter. One embodiment of the present invention relates to a memory device, a processor, a driving method thereof, or a manufacturing method thereof.
Note that in this specification and the like, a semiconductor device generally means a device that can function by utilizing semiconductor characteristics. Thus, a semiconductor element such as a transistor or a diode and a semiconductor circuit are semiconductor devices. A display device, a light-emitting device, a lighting device, an electro-optical device, an electronic appliance, and the like may include a semiconductor element or a semiconductor circuit. Thus, a display device, a light-emitting device, a lighting device, an electro-optical device, an electronic appliance, and the like may include a semiconductor device.
2. Description of the Related Art
In recent years, liquid crystal elements have been extensively researched and developed as a display element used in a display region of a display device. In addition, light-emitting elements utilizing electroluminescence (EL) have been extensively researched and developed. In a basic structure of a light-emitting element, a layer containing a light-emitting substance is interposed between a pair of electrodes. Voltage is applied to the light-emitting element to obtain light emission from the light-emitting substance.
The light-emitting element is a self-luminous element; thus, a display device using the light-emitting element particularly has advantages such as high visibility, no necessity of a backlight, and low power consumption. In addition, the light-emitting element has advantages in that the element can be manufactured to be thin and lightweight and has high response speed.
A display device including the display element can be flexible; thus, the use of a flexible substrate for the display device has been proposed.
As a method for manufacturing a display device using a flexible substrate, a technique has been developed in which a semiconductor element such as a thin film transistor is manufactured over a substrate such as a glass substrate or a quartz substrate, for example, a space between the semiconductor element and another substrate is filled with an organic resin, and then the semiconductor element is transferred from the glass substrate or the quartz substrate to the other substrate (e.g., a flexible substrate) (Patent Document 1).
In some cases, over a light-emitting element that has been formed over a flexible substrate, another flexible substrate is provided in order to protect a surface of the light-emitting element or prevent entry of moisture or impurities from the outside.
Display devices are expected to be applied to a variety of uses and become diversified. For example, a smartphone and a tablet with a touch sensor are being developed as portable information appliances.